Roofing

Due to the harmful effects of grease and oil on all roofing systems, most major roofing manufacturers will recommend or specify a rooftop grease containment system for areas that will be exposed to grease and oil. The damaging effects to the roof shorten its life and increase the likelihood for premature roof repairs and replacements, costing building owners thousands of dollars.

When obtaining a warranty for a building that has known grease and oil problems, it is standard operating procedure to submit information on the grease containment system to the Technical Services Department. In addition, approval of the grease containment system must be obtained for your warranty at the time of installing the re-roof or new roof. Most roofing manufacturers will not extend a blanket authorization; they will give approvals on a site-specific nature. Facilitec recommends that you talk to the Technical Services Department of your roofing manufacturer to make sure you are covered with the proper grease containment solution for your needs.

ROOFING TERMINOLOGY

ABRASION RESISTANCE

The ability of the membrane to resist mechanical abrasion such as foot traffic and wind-blown particles which tend to progressively remove materials from the membrane's surface.

ADHESION

The ability of the membrane to remain adhered to the substrate or to itself during its service life.

AGGREGATE

Crushed stone or water-worn gravel used for surfacing or ballasting.

ALUGATORING

A term describing the defect in an applied coating or mastic when it shrinks or cracks into large segments. When the action is fine and incomplete it is usually referred to as "checking."

ALLOY

A mixture or blend of similar materials (thermoplastic) melted and reextruded into a new material from which the original materials cannot be separated.

Temperature between which it is usually safe to apply finishes, adhesives and sealants.

ASPHALT

A brown to black bitumen found in natural beds or obtained as a residue from petroleums.

ASPHALT COATINGS

Asphalt coatings fall within three general categories: cutbacks, emulsions and modified. Each has a different composition.

ATACTIC

A polymer in which there is a random arrangement of pendent groups on each side of the chain, as in Atactic Polypropylene (APP).

BACKNAILING

The practice of back nailing in addition to hot-mopping all the plies to a substrate to prevent slippage.

BASE SHEET

Saturated or coated felt placed as the first ply in a multi-ply built-up roofing membrane.

BATTEN

A strip of steel or aluminum used to mechanically fasten a single-ply membrane for the purpose of preventing wind uplift. Type of metal roofing seam; raised rib in a metal roof, or a separate part of formed portion in a metal roofing panel.

BITUMEN

An asphalt, various mixtures of hydrocarbon material of natural or pyrogenous origin (as coal tar), or combinations of both, which may be liquid, semi-solid, or solid, and which is completely soluble in carbon disulfide. Any number of inflammable mineral substances.

BLANKET INSULATION

Fiberglass insulation in roll form, used with a vapor retarder membrane laminated to the inside face.

BLIND RIVET

A rivet applied from one side, incorporating a stem which pulls against material on the blind side and "pops" off when the rivet is fully formed.

BLOWING AGENT

A gas or a substance capable of producing a gas used in making formed materials.

BOND

The adhesive and cohesive forces holding two roofing components in contact.

BUILDING CODE

Any system of principles or rules set to control, design and construct buildings or materials.

BUILT-UP ROOF (BUR)

A roofing membrane built up on the job, made of several sections or layers of bitumen fastened together with felts. The top can be finished with crushed slag or gravel.

BUTYL RUBBERS

Butyl rubber is an elastomer that has extremely low water vapor and gas permeability. Having the lowest permeability in comparison to other elastomers, it is especially recommended in situations which have relatively higher vapor drives, such as low-temperature applications (water coolers, freezers, and cryogenic storage) or water immersion (water storage and ponding water). When exposed to exterior weathering or in areas where mechanical damage may occur, butyl rubbers should be topcoated with tougher or more weatherable coatings (see coating manufacturers for specific recommendations). While most butyl rubbers are two-component materials, some single-component versions are available.

CALENDER

A machine normally composed of three counter-rotating steel rolls of large diameter; a device used to produce film and sheet goods that are normally wound up into roll stock.

CANT STRIP

A continuous strip of material (triangular in cross-section) used as a transition between the roof deck and a vertical surface; normally has a 45° sloping surface.

CAP SHEET

The top sheet of BUR forming the finished surface of the roof.

CHLOITINATED POLYETHYLENE (CPE)

A thermoplastic sheet composed of high molecular weight, low-density polyethylene that has been chlorinated to a given level.

A pre-formed shape used to fill the space between ribs on a metal panel.

COAL TAR PITCH

Dark brown to black solid hydrocarbon obtained from the residuum of the distillation of coke-oven tar, used as the water-proofing agent of dead-level or low-slope built-up roofs. It comes in a narrow range of softening points - from 129° to 144°F.

COATED BASE SHEET

Roofing felt that is coated with asphalt, usually on both sides, then (or Felt) surfaced with an anti-stick material.

DISPERSION

A heterogeneous system in which a finely divided material is distributed in another material. Note: dispersion is usually the distribution of a finely divided solid in a liquid or a solid; for example, pigments or fillers in coatings. A dispersion of a liquid in another liquid is an emulsion.

DUCTILITY

The property of the material to withstand deformation by stretching without recovery of shape upon removal of the stretching force.

EAVE

The low edge of a sloping roof.

EDGE VENTING

The practice of providing regularly spaced openings at a roof perimeter to relieve the pressure of water vapor entrapped in the insulation.

ELASTOMER

Any of several elastic substances that, at room temperature, resemble and display the qualities of rubber.

EUSTOPUSTIC

A substance that exhibits a greater or lesser resiliency and will return to, or almost return to, its original size and shape if deformed to some extent below its elastic limit, as opposed to a brittle substance. A trade description used to identify elastomeric and plastomeric types of singleply roof membranes.

ELONGATION (STRETCH)

Lengthening or stretching ability to accommodate movement.

EQUIVISCOUS TEMPERATURE

The optimum temperature for applying bitumen. At this temperature, the bitumen will be about as fluid as 20-weight oil. (Approximately 125 Centistokes.) When asphalt is mopped between felts, it yields approximately 23 lbs. when applied at the equiviscous temperature.

ETHYLENE INTERPOLYMER ALLOY (EIP)

Generic term for Elvaloy (a registered trademark of E.I. Du Pont de Nemours & Co.), a very dense molecular resin with exceptional fire-resistant and chemical-resistant properties.

ETHYLENE MONOMER (EPDM)

Material synthesized from ethylene, propylene and small amounts of PROPYLENE DIENE diene monomer.

EXPANSION JOINT

A joint where movement is allowed to take place, usually in response to thermal stress.

EXTRUSION

Process of extruding or forcing a material (under heat and pressure) through a die of specified shape. Plastic and aluminum materials may be extruded into various shapes by this process.

FACTORY MUTUAL ENGINEERING & RESEARCH CORP.

Organization located in Norwood, MA, that classifies roof assemblies on their fire characteristics and wind uplift resistance for insurance companies in the United States.

FIRE RESISTANCE

The property of a material or assembly to withstand fire or give protection from it. As applied to elements of buildings, it is characterized by the ability to confine a fire or to continue to perform a given structural function, or both.

FISHMOUTH

An opening formed by an edge wrinkle in the felt.

FLAME SPREAD

(1) The rate of flame movement across an exposed deck. (2) The measurement of how much product contributes to the fire spread (determined under controlled and standardized test conditions). Refer to ASTM Designations E84 or El 62.

FLASHING

Sheet metal, felts or elastomeric sheet used in waterproofing roofvalleys or hips or the angle between a wall and roof and ail joints.

FLASHING CEMENT

A trowelable, plastic mixture of bitumen and asbestos (or other inorganic) reinforcing fibers, and a solvent.

FLOOD COAT

The top layer of bitumen in an aggregate-surfaced, built-up roofing membrane. Correctly applied, it's poured, not mopped, to a weight of 60 lbs. per square for asphalt and 75 lbs. per square for coal tar pitch.

FLUTTER FATIGUE

The fatigue action a single-ply membrane may experience in a high wind situation, causing a complete stress reversal to occur rapidly; temperature may influence the flutter fatigue resistance of the membrane material.

GABLE

Same as rake; also, the triangle formed by two sloping roof edges and the horizontal line connecting them.

GAGE, GAUGE

A designation of metal thickness.

GALVANIZED

Zinc coating on steel for corrosion resistance.

GRAVEL STOP

Flanged device, normally metallic, designed to prevent loose aggregate from washing off the roof and to provide a finished edge detail for the built-up roofing assembly.

GUTTER

Drainage trough at the low edge of a sloping roof.

HEAT AGING

Submitting a membrane to prolonged elevated temperatures to determine if its physical properties are adversely affected.

"HOT STUFF" OR HOT

Roofers term for hot bitumen.

HYPALON COATINGS

Hypalons (a registered trademark of E.I. DuPont de Nemours & Co.) are elastomeric coatings based on chlorosulfonated polyethylene rubbers. They are fast-drying single-package materials that have exceptional fire retardancy, chemical resistance, weathering properties, and moisture vapor transmission resistance. They may be used as the entire coating system or as a topcoat over other generic coatings.

ICBO

International Conference of Building Officials. Uniform Building Code.

IMPACT

Capability to withstand mechanical or physical abuse under severe RESISTANCE service conditions. Resistance to blows, bumps and shocks incident to use.

INCLINE

The slope of a roof, expressed in the number of vertical units of rise per horizontal units of run, or in percent. (See Slope; Pitch).

INORGANIC

Being or composed of material other than hydrocarbons and their derivatives; not of plant or animal origin.

INSTRON

Brand of instrument utilized in the stress-strain testing of materials.

INTERIOR GUTTER

A gutter hidden behind an outside wall or located inside a building.

LAMINATION

Process of joining thin layers of material together under heat and pressure (with an adhesive) into a finished product.

LAP

The part of a roofing membrane that covers the preceding course in any overlapping situation.

LEADER

Same as downspout.

LIVE LOADS

Moving or non-permanent loads such as wind, snow, ice, rain or portable equipment.

LOW-TEMPERATURE

Lowest temperature at which a material can withstand a bending FLEXIBILITY test around a mandrel of specified shape.

MANSARD

A nearly vertical roof, typically a fascia.

MEMBRANE

Continuous flexible (or semi-flexible) roof covering that forms the water control element of a roofing system. It is normally assembled on site from single or multiple plies of material, e.g., polyvinyl chloride roofing in single-ply systems and bituminous felt roofing in multiple-ply systems.

MEMBRANE

Woven or non-woven fabrics used for saturation and embedment in REINFORCEMENT mastic and coating applications to provide strength, continuity and impact resistance.

A broad class of materials (and blends) that can be used to change the performance characteristics of a roofing grade asphalt.

MODULUS OF ELASTICITY

The ratio of stress corresponding to strain (within the elastic limit of a material); it is a measure of the stiffness of a material.

MONOUTHIC

Single form or single piece; formed or composed of material without joints or seams.

MOPPING

An installation of bitumen applied with a mop or mechanical device to the substrate or to the felts of a built-up roofing membrane.

NEOPRENE RUBBER

A synthetic rubber having physical properties closely resembling those of natural rubber, but not requiring sulphur for vulcanization. It is made by polymerizing chloroprenes, produced from acetylene and hydrogen chloride.

SBS

Styrene-butadiene-styrene block copolymer, with domains having the properties of the pure homopolymers but contained in the same molecule.

SCRIM

A thin reinforcing mat usually non-woven and normally made of glass or polyester fiber.

SEAM

A lap or area of juncture for two separate sheets

SELF-IGNITION

The minimum temperature at which the self-heating properties TEMPERATURE of a material lead to ignition in the absence of an outside ignition source. It is dependent upon specimen size, heat loss conditions and possible other variables, such as moisture content.

SELVAGE

A sheet edge or edging which differs from the main part of the finished roof sheet.

SELVAGE EDGE

A lapped joint detail for mineral-surfaced cap sheets, in which the main surfacing is omitted for 2 in. of the 36-in.-width, so that the overlapping side will get better adhesion.

SERVICE TEMPERATURE LIMITS

The limiting temperatures at a coated surface within which limits the applied coating will have satisfactory performance.

SQUARE

Measure of roofing materials equaling 100 square feet.

TENSILE STRENGTH

The force per unit of the original cross sectional area (of an unstretched specimen) which is applied at the time of rupture of the specimen. It is calculated by dividing the breaking force in pounds by the cross section of the unstretched specimen in square inches.

THF

Abbreviation for tetrahydrofuran, a solvent used to weld together some thermoplastic materials, such as PVC.

THERMAL BARRIER

An insulated separation between hot and cold air masses.

THERMAL MOVEMENT AND SHOCK RESISTANCE

The roofing system shall withstand sudden and frequent changes in temperature.

THERMALSHOCK

The stress-producing phenomenon resulting from sudden temperature changes in a roof membrane.

THERMAL (HOT-AIR) WELDING

The joining of two, clean, separate surfaces by applying heat from an electric heat gun. Used with thermoplastic materials like PVC, CPE and CSPE.

THERMOPLASTIC

Capable of being repeatedly softened by increase of temperature and hardened by decrease of temperature. Note: Thermoplastic applies to those materials whose change upon heating is substantially physical.

THERMOSETTING

Material which cannot be reshaped or formed by heating; cured synthetic rubber sheet materials (EPDM, Butyl, etc.) are thermosets.

WATER VAPOR PERMEANCE

The water vapor transmission of a material under unit vapor pressure difference between two specific surfaces. An acceptable unit of permeance is the perm.

About Us

Facilitec Southwest is the leading provider of Restaurant Kitchen Exhaust Cleaning Services and Rooftop Grease Containment products in the Southwest United States. Our satisfied customers include chain and independent restaurants, hotels, casinos, hospitals, supermarkets, country clubs, schools, cafeterias, food processing and industrial organizations. Give us a call and let us show you what we can do for your establishment. We are fully insured and bonded.

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